velopment, structure, and functions of the social aggregate, as brought about by the mutual actions of individuals whose natures are partly like those of all men, partly like those of kindred races, partly distinctive.
These phenomena of social evolution have, of course, to be explained with due reference to the conditions each society is exposed to—the conditions furnished by its locality and by its relations to neighboring societies. Noting this merely to prevent possible misapprehensions, the fact which here concerns us is, not that the Social Science has these or those special characters, but that, given men having certain properties, and an aggregate of such men must have certain derivative properties which form the subject-matter of a science.
"But were we not told some pages back that, in societies, causes and effects are related in ways so involved that prevision is often impossible? Were we not warned against rashly taking measures for achieving this or that desideratum, regardless of the proofs, so abundantly supplied by the past, that agencies set in action habitually work out results never foreseen? And were not instances given of all-important changes that were due to influences from which no one would have anticipated them? If so, how can there be a Social Science? If Louis Napoleon could not have expected that the war he began to prevent the consolidation of Germany would be the very means of consolidating it; if to M. Thiers, five-and-twenty years ago, it would have seemed a dream, exceeding all ordinary dreams in absurdity, that he would be fired at from his own fortifications, how in the name of wonder is it possible to formulate social phenomena in any thing approaching scientific order?"
The difficulty, thus put in as strong a form as I can find for it, is that which, clearly or vaguely, rises in the minds of most to whom Sociology is proposed as a subject to be studied after scientific methods, with the expectation of reaching results having scientific certainty. Before giving to the question its special answer, let me give it a general answer.
The science of Mechanics has reached a development higher than has been reached by any but the purely abstract sciences. Though we may not call it perfect, yet the great accuracy of the predictions which its ascertained principles enable astronomers to make, shows how near to perfection it has come; and the achievements of the skilful artillery-officer prove that, in their applications to terrestrial motions, these principles yield previsions of considerable exactness. But now, taking Mechanics as the type of a highly-developed science, let us note what it enables us to predict, and what it does not enable us to predict, respecting some concrete phenomenon. Say that there is a mine to be exploded. Ask what will happen to the fragments of matter sent into the air. Then observe how much we can infer from estab-
